The Superstack is located on top of the largest nickel smelting operation in the world at Vale's Copper Cliff processing facility in the city of Greater Sudbury.

[7] In addition to further reducing sulphur dioxide emissions by 85 per cent, the decommissioning of the stack was expected to cut the complex's natural gas consumption in half.

The Copper Cliff smelter was already home to some of the world's tallest stacks, including two 500 ft (150 m) chimneys constructed in 1928-29 and 1936.

[11] However, these proved to be insufficient and compounded by open coke beds in the early to mid-20th century and logging for fuel, an inevitable near-total loss of native vegetation occurred.

Of particular interest to geologists are the now exposed rocky outcrops, which have been permanently stained charcoal black, first by the pollution wafting over the decades from the roasting yards, then by the acid rain in a layer which penetrates up to three inches into the once pink-grey granite.

As a result, these gases could be detected in the atmosphere around Greater Sudbury in a 240 kilometres (150 mi) radius of the Inco plant.

During the 1970s and 80s, the sulphur dioxide plume formed a permanent, opaque, cloud-like formation running across the entire horizon as seen from a distance.

[citation needed] Construction of the Superstack was followed by an environmental reclamation project which included rehabilitation of existing landscapes and selected water bodies such as Lake Ramsey.

It would remain on "hot standby" for about two months while the replacement flue connections were tested but the stack would then be demolished over the years.